Privacy
Nothing is collected, because there is nowhere for it to go.
No account, no server
There is no sign-up, no login and no backend. The whole app runs on your machine, and the site is a set of static files. Nothing you type, play or arrange is sent anywhere.
Where your songs are
In your browser's local storage, on the device you wrote them on. They are not synchronised, not backed up and not visible to anyone else, which is the privacy guarantee and the risk in the same sentence. Clearing site data removes them.
No analytics and no cookies
This site sets no cookies and loads no third-party scripts: no analytics, no tag manager, no fonts fetched from somebody else's domain, no embedded players. Which is also why there is no cookie banner: there is nothing to ask about.
What the host sees
The site is served by GitHub Pages. Like any web host, it processes the requests it receives, which is the address asked for, the IP it came from and the browser that asked, as part of delivering the page and keeping the service up. That is GitHub's processing, under their privacy statement, and this site neither adds to it nor receives a copy of it.
The sampled instruments
The drum and bass samples are files served from this same site, like any other asset. Playing them tells nobody anything.
Questions
Support is where to ask. When the imprint is published it will name who is responsible for this site.